Heterocyclic compounds in which an oxygen is attached to a cyclic nitrogen.

Synonyms: Heterocyclic N Oxides, 0, Cyclic N Oxides, Cyclic N-Oxides, Oxides, Cyclic N, N Oxides, Cyclic, N-Oxides, Heterocyclic, N-Oxides, Cyclic, Heterocyclic N-Oxides